1. Field of the Invention
This invention relates to a chilling system using a refrigerant to chill or cool a load.
2. Description of the Invention
A conventional system illustrated in FIG. 3 includes a chilling circuit a which is connected to a heat-producing load H.
The chilling circuit a includes a pump p for circulating a secondary cooling water through the circuit a, and a buffer tank t for temporarily storing the secondary cooling water. Heat exchanging is implemented during a process in which the secondary cooling water is passed through the load H to absorb heat generated by the load H.
Due to the absorption of heat generated by the load H as described above, the secondary cooling water increases in temperature. However, the heat of the secondary cooling water is dissipated by a chiller b as described below.
The chiller b is composed of a main heat exchanger 1 connected to the above circuit a; a circulation circuit 2 connected to the main exchanger 1 and circulating a refrigerant gas; a compressor C connected to the circulation circuit 2; and a heat exchanger 3 for dissipating heat of the refrigerant gas to the outside.
The dissipation heat exchanger 3 is connected to a piping 4 for introduction of a primary cooling water through the piping 4. The primary cooling water is city water, industrial water cooled by a cooling tower, or the like, temperature of which varies depending on the season but is held within a range of 10 degrees Celsius to 30 degrees Celsius. A supply flow rate of the primary cooling water is controlled by a valve (not shown) to chill the refrigerant gas to a predetermined temperature.
In the chiller b designed as described above, the compressor C increases the pressure and temperature of the refrigerant gas to high levels. The refrigerant gas at high pressure and high temperatures is compressed and liquefied by the dissipation heat exchanger 3. The liquefied refrigerant is evaporated in the main heat exchanger 1 for absorbing the heat of the secondary cooling water.
The secondary cooling water reaching high temperatures by absorbing the heat of the load H can be thus chilled or cooled.
As described above, the chiller b is configured such that the secondary cooling water flowing through the chilling circuit a is chilled with the refrigerant gas. This produces the need for maintaining the temperature of the refrigerant gas below the temperature of the secondary cooling water at all times. Hence, the conventional system always allows the compressor C to operate.
Such conventional systems have a problem associated with significant energy use energy because the compressor C of the chiller b must be operated at all times.
As outside air temperature decreases in winter, the temperature of the primary cooling water decreases. Hence, with the ability of the dissipation heat exchanger 3 alone, the refrigerant gas can be decreased to a predetermined temperature.
Even in this event, however, the conventional system causes the compressor C of the chiller b to operate at all times, resulting in uselessly expending energy.
It is an object of the present invention to provide a chilling system which achieves a reduction in the amount of energy expended and also in energy loss.
A first aspect of the present invention is characterized by including a load; a chilling circuit for chilling or cooling the load with a refrigerant; a heat-dissipating mechanism for dissipating heat of the refrigerant in the chilling circuit to the outside; a refrigerant tank connected to the chilling circuit via a confluent valve; a chiller for maintaining the refrigerant stored in the refrigerant tank at a predetermined temperature; a controller for controlling the degree of valve opening of the confluent valve; and a temperature sensor for detecting a temperature of the refrigerant in the chilling circuit, and in that when the temperature sensor detects that a temperature of the refrigerant in the chilling circuit exceeds a predetermined temperature, the controller opens the confluent valve in order to mix the refrigerant in the refrigerant tank into that in the chilling circuit, and when the refrigerant stored in the refrigerant tank is maintained at a temperature within a predetermined range, the chiller stops its operation.
According to the first aspect, the chiller stops its operation as long as the refrigerant in the refrigerant tank is maintained at a predetermined temperature. For this reason, as compared with the conventional system which requires the continuous operation of the compressor of the chiller, energy is saved.
In the first aspect, a second aspect of the present invention is characterized in that the heat-dissipating mechanism is of a water cooling type and introduces industrial water or city water serving as cooling water.
According to the second aspect, industrial water or city water is used as the refrigerant for the dissipation heat exchanger. For this reason, there is not a need for using an extra power source, resulting in minimizing the expended energy.